Anti-inflammation Of Natural Components From Medicinal Plants At A Low Concentration In Brain Via Inhibiting Neutrophil Infiltration After Stroke

Inflammation after stroke consists of activation of microglia/astrocyte in situ and infiltration of blood-borne leukocytes,resulting in brain damage and neurological deficits.Mounting data demonstrated that most natural components from medicinal plants had anti-inflammatory effects after ischemic stroke through inhibiting activation of resident microglia/astrocyte within ischemic area.But,it is speculated that this classical activity cannot account for the anti-inflammation of these natural components in the cerebral parenchyma,where they are found at very low concentrations due to their poor membrane permeability and slight leakage of BBB.Could these drugs exert anti-inflammation peripherally infinitized by BBB permeability? Factually,ameliorating blood-borne neutrophil recruitment in peripheral circulatory system has been proved to reduce ischemic damage and improve outcomes.Thus,it is concluded that if drugs could achieve efficient concentration in the cerebral parenchyma,they can function via crippling resident microglia/astrocyte activation and inhibiting neutrophil infiltration,whereas the latter will be dominating when these drugs localized at a low concentration in the brain.In this review,the availability of some natural components to cross the BBB in stroke will be discussed,and how these agents lead to improvements in stroke through inhibition of neutrophil rolling,adhesion and transmigration will be illustrated.